Weak toFighting ×1.6

Attacker	Type	Moveset	DPS
Lucario	FightingSteel	Force PalmAura SphereLegacy	34.1
Pheromosa	BugFighting	Low KickFocus Blast	31.2
Terrakion	RockFighting	Double KickSacred SwordLegacy	31.1
Blaziken	FireFighting	CounterAura Sphere	30.8
Kartana	GrassSteel	Fury CutterSacred Sword	29.4
Conkeldurr	Fighting	Force PalmFocus Blast	28.4
Keldeo	WaterFighting	Low KickSacred Sword	28.1
Breloom	GrassFighting	Force PalmDynamic Punch	28.1
Urshifu	Fighting	CounterDynamic Punch	27.9
Eternatus	PoisonDragon	Poison JabDynamax CannonLegacy	27.7
Marshadow	FightingGhost	CounterClose Combat	27.2
Mewtwo	Psychic	CounterFocus BlastLegacy	27.1

Overcast boosts the Fighting attacks above. Partly cloudy boosts Slaking.

Level 40, 15 attack IV, costed against Slaking's own defense and typing, one per evolution family.

Slaking's moveset, CP and shiny All counters Raid board

Questions people ask

What is Slaking weak to in Pokémon GO?

Slaking takes 1.6 times from Fighting.

What's the best counter to Slaking?

Lucario with Force Palm and Aura Sphere, worth 34.1 damage per second against Slaking's own defense. The full ranking is above.